1. Field of the Invention
The present invention is related to an optical element provided with a lens and an optical function element. Further, the present invention is related to an optical element wafer provided with a plurality of optical elements, such as a plurality of lenses and a plurality of optical function elements, in a wafer state. Further, the present invention is related to an optical element wafer module in which the plurality of optical element wafers are laminated. Further, the present invention is related to an optical element module, which is made by cutting the optical element wafer or the optical element wafer module, and a method for manufacturing the optical element module. Further, the present invention is related to an electronic element wafer module in which the optical element wafer or optical element wafer module is modularized with an electronic element wafer. Further, the present invention is related to a method for manufacturing an electronic element module, in which the electronic element wafer module is cut simultaneously or the optical element or the optical element module is modularized with an electronic element. Further, the present invention is related to an electronic element module manufactured by the method for manufacturing the electronic element module. Further, the present invention is related to an electronic information device, such as a digital camera (e.g., a digital video camera or a digital still camera), an image input camera, a scanner, a facsimile machine, a camera-equipped cell phone device and a television telephone device, including the electronic element module used therein.
2. Description of the Related Art
Further downsizing and lowering the cost are requested for a camera-equipped cell phone device and a personal digital assistant (PDA) and so on as conventional optical devices that include an image capturing element and a light-focusing lens element thereabove.
In response to such a request, Reference 1 proposes a method for obtaining an image capturing element module, the method including the steps of: forming and connecting an image capturing element for performing a photoelectric conversion on and capturing an image of incident light and a lens element thereabove for focusing light at a wafer level; modularizing the image capturing element and the lens element as an image capturing element wafer module, which functions as an electronic element wafer module; and individualizing the modularized image capturing element wafer module by simultaneous cutting. According to the method, a transparent substrate is adhered above a semiconductor wafer having an image capturing element at the center portion, with a spacer interposed therebetween. A convex lens is formed as a light-focusing lens element on the transparent substrate in a closely-adhered manner. This image capturing element module will be described in detail with reference to FIG. 28.
FIG. 28 is an essential part longitudinal cross sectional view illustrating one exemplary structure of a conventional image capturing element wafer module at a time of simultaneous cutting.
In FIG. 28, a conventional image capturing element wafer module 100 includes: an image capturing element wafer 102, in which a plurality of image capturing elements 101 are arranged in a matrix, the image capturing elements 101 including a plurality of light receiving sections for performing a photoelectric conversion on and capturing an image of image light from a subject; a resin adhesion layer 103 formed on the image capturing element wafer 102 and in between the image capturing elements 101; a transparent substrate 104 covering the image capturing element wafer 102 and adhered and fixed on the resin adhesion layer 103; and lens elements 105 provided on the transparent substrate 104 in such a manner to correspond to the plurality of image capturing elements 101 respectively. In addition, a cut-securing tape 106, which is adhered on a back surface side during cutting, is adhered on a convex lens surface of the lens element 105. Maintaining this state, the image capturing element wafer module 100 is simultaneously cut along dicing lines DL between adjacent image capturing elements 101.
According to Reference 1, as illustrated in FIG. 29, a camera device 200 includes: a cover plate 203 provided above an image capturing element 201 with a minute spacer plate 202 interposed therebetween; and a lens plate 205 provided above the cover plate 203 such that the center of the image capturing element 201 corresponds to an optical axis C of a protruded lens 204. In this case, a cut-securing tape, which is adhered on aback surface side during cutting, is adhered on a convex lens surface of the lens 204, and the camera device 200 is cut simultaneously along dicing lines DL between adjacent image capturing elements 201.
Furthermore, Reference 2 discloses an example where a lens is formed in each of a plurality of through holes of a lens substrate. It is conceived that a plurality of such lens wafer modules are laminated on an image capturing element wafer to be modularized. FIG. 30 illustrates this module.
FIG. 30 illustrates a lens wafer disclosed in Reference 2, and is an essential part longitudinal cross sectional view illustrating an image capturing wafer module, in which a plurality of lens wafers are used with lenses provided in a plurality of through holes of a lens substrate and the lens wafers are modularized with an image capturing element wafer.
In FIG. 30, an image capturing element wafer module 250 includes: an image capturing element wafer 252, in which a plurality of image capturing elements 251 are arranged in a matrix, the image capturing elements 251 including a plurality of light receiving sections for performing a photoelectric conversion on and capturing an image of image light from a subject; and a transparent support substrate 254 with a resin adhesion layer 253 interposed therebetween, part of which is removed above the image capturing element 251. A lens wafer module 255 is provided being adhered on the transparent support substrate 254, the lens wafer module 255 being provided such that each lens position corresponds to each of the plurality of image capturing elements 251. The lens wafer module 255 is provided with a lens substrate 256 in such a manner to fill an outer circumference area of a lens, and a lens wafer 255a is configured to be adhered on a lens wafer 255b by an adhesive 257 herein. In addition, on a front surface side of the lens wafer 255a, a light shielding plate 258 with an opening (hole) on an optical surface A is provided by being adhered by the adhesive 257. Further, the transparent support substrate 254 is adhered with the lens wafer 255b by the adhesive 257. The adhesive 257 is provided in an area having a predetermined width on an outer circumference side of the openings of the light shielding plate and the lens substrate 256 as well as along each side inside of square or rectangular dicing lines DL on the outer circumference side of the circular optical surface A at the center, when viewing the image capturing element wafer module 250 of FIG. 31, as illustrated in FIG. 30.
The image capturing element wafer module 250 is illustrated in FIG. 30 with a unitary module cross-sectional structure; however, a large number of the unitary module cross-sectional structures are arranged in a matrix of row and column directions. The unitary module cross-sectional structure is an image capturing element module after the individualizing along the dicing lines DL.
In References 3 as illustrated in FIG. 32, an object lens 300 includes: a substrate 302 with a first lens 301 formed therein; a substrate 304 with a second lens 303 formed therein; and an adhesive 305 for adhering and fixing the substrates 302 and 304 with the first lens 301 and the second lens 303, the substrates facing the respective lenses. A light-absorbing heating element 306 is formed in the outer periphery of the substrate 302, a light-absorbing heating element 307 is formed on the outer circumference side of the first lens 301 and inside the substrate 302, a light-absorbing heating element 308 is formed on the outer circumference side of the second lens 303 and inside the substrate 304, and a light-absorbing heating element 309 is formed in the outer periphery of the substrate 304, each of which is formed at a position not shielding each optical path of the first and second lenses 301 and 303. The first lens 301 and the second lens 303 are provided facing with each other with respective optical axes aligned in a space portion 310 between the substrates 302 and 304.
Reference 1: Japanese Laid-Open Publication No. 2004-63751
Reference 2: Japanese Laid-Open Publication No. 2005-539276
Reference 3: Japanese Laid-Open Publication No. 2003-203374